"Green" Belts

Hi All,


I had a new to me mechanic on the boat today to do valve adjustments on both of my motors, which are Yanmar 4LHA-STP.



He noticed that I fight with belt dust on both motors and recommended that I switch to the "green" belts, but he couldn't remember the brand name. I did a little google search and I found Gates green label belts, but no green belts. Any idea what he means?


The belts on the 4LHA are too small, it's super hard to keep them at the right tension so they make a ton of dust. I've done better keeping them a little loose, but he felt like they are too loose. I've looked at the serpentine kits, but man they are expensive and hardly seem worth it unless I upgrade the alternators, even more $.


I've checked alignment, checked the pulleys for rust, all looks good, they just slip.

Sorry, can't help you on the 'green' front, but when I switched to cogged belts the dust problem disappeared.

MurrayM said:

Sorry, can't help you on the 'green' front, but when I switched to cogged belts the dust problem disappeared.

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That meant changing the pulleys, correct?

Dougcole said:

That meant changing the pulleys, correct?

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Nope. They are 'V' belts, just notched/incised on the inner surface. I rummaged around on the Interweb and found a photo that illustrates their shape. (These aren't the belts I use (NAPA) just a photo that looks similar).

https://mechanidrive.com/17420-oem-automobile-replacement-belt/

You also might want to wait for opinions from more experienced people than I

If the alignment is good, are they bottoming out on the pulleys?

Dougcole said:

Hi All,

He noticed that I fight with belt dust on both motors and recommended that I switch to the "green" belts, but he couldn't remember the brand name. I did a little google search and I found Gates green label belts, but no green belts. Any idea what he means?

Click to expand...

He is probably referring to Gates Green Stripe® V Belts. I've used them with Yanmar power in the past which eliminated belt dust and slippage. I've also used them on high performance automotive engines for decades with the same results. Highly recommended.

I just went through this exercise of trying to find better belts.

Gates very heavy duty V belts are called Fleetrunner and the tops are solid green. (Not to be confused with their green stripe belts). If you have a number from another belt you should be able to cross reference to the Gates belt. You can tell the Fleetrunner green topped belts by the HD designation after the 4 digit Gates number.

For sample, the Gates HD belt for the Ford Lehman 135 is 9476HD.

https://www.gates.com/us/en/search.p.8531-000000-000016.v.8711-00476.html

Oops, sorry Larry you posted while I was writing. My comment on the Green Stripe belts was not directed at you. In fact, the Green Stripe belts also seem to be for heavy duty use so I don’t know which one is better of if they’re both good.

Ken

Take a look at the Gates Powerated V Belts. They are designed for industrial use.

If you are using twin belts , many sizes can be ordered as a matched pair.

Green belts are considered industrial quality, heavier duty than standard automotive belts.

Took a little poking around, but I found it and ordered a pair. Thanks guys, I hope it will help.

Doug
I put on the above recommended belt on my Yan 6LYA and it did seem to reduce dust. Mine is marked as both Fleetrunner and Green Stripe.

Thanks Don.


I ordered two of the below belts.


https://www.amazon.com/gp/product/B00D0IDTIE/ref=ox_sc_act_title_1?smid=A22LWEMCXESXCG&psc=1


It was a little confusing because Gates doesn't list a belt on their site for the 4LHA-STP, but they do list one for a couple of other 4LH motors. I found other sites that show those motors as using the same belt as the 4LHA, so I assume that the Gates belt will work.

Should be able to order by length. Sometimes alternators get changed and that changes belt size. You old belt number should have the length coded into it's number.

And yes, the 4LH has a rep as a belt eater. Lots of torsional activity in the crank nose. Raises heck with belts. Want to use the best belt you can find.

Gates makes good stuff. Hope it works.

Ski in NC said:

Should be able to order by length. Sometimes alternators get changed and that changes belt size. You old belt number should have the length coded into it's number.

And yes, the 4LH has a rep as a belt eater. Lots of torsional activity in the crank nose. Raises heck with belts. Want to use the best belt you can find.

Gates makes good stuff. Hope it works.

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Thanks Ski. The yanmar number on my old belt is 121850-42280. Would that somehow tell me the length?

Doug
FYI Advanced Auto Parts carries their own branded Fleet Runner belts that are green and notched. I just picked up a spare for the one I recently changed. They use the same numbering as Gates and look identical but have no idea who makes them?

yes, I purchased the "Green Belts" as a NAPA brand.

NAPA huh? Oh, NOW y'all tell me. I see how you are.

NAPA/Gates 9476HD's on my Lehman 120.

kchace said:

I just went through this exercise of trying to find better belts.

Gates very heavy duty V belts are called Fleetrunner and the tops are solid green. (Not to be confused with their green stripe belts). If you have a number from another belt you should be able to cross reference to the Gates belt. You can tell the Fleetrunner green topped belts by the HD designation after the 4 digit Gates number.

For sample, the Gates HD belt for the Ford Lehman 135 is 9476HD.

https://www.gates.com/us/en/search.p.8531-000000-000016.v.8711-00476.html

Oops, sorry Larry you posted while I was writing. My comment on the Green Stripe belts was not directed at you. In fact, the Green Stripe belts also seem to be for heavy duty use so I don’t know which one is better of if they’re both good.

Ken

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Gates 9470 is the correct belt. HD is simple heavy duty.
This assumes the original pulleys are on alternator. (Can't imagine why they wouldn't be.) I believe the width is 1/2" and depth is 3/8".

If there is still excessive dust you will need to shim your alternator mounts to align the pulleys.

Do not store transmission belts in the engine room. Heat kills their longevity.

LarryM said:

He is probably referring to Gates Green Stripe® V Belts. I've used them with Yanmar power in the past which eliminated belt dust and slippage. I've also used them on high performance automotive engines for decades with the same results. Highly recommended.

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Gates Green Stripe all the way. I used them for a 351CU Cleveland in my Pantera that was pulling over 350 HP and destroying lesser belts. I bought a spare at the same time thinking the Gates would only last a while - it outlasted my ownership (20 years). I don't recall any dust in the housing, but that was not critical to me.
~A

Belt dust on alternator belt

I had this problem on an older motor with an aftermarket higher amp alternator. Just burned through the regular belts as the horsepower needed to drive the alternator caused the belt to wear out.
One solution is to put a wider pulley and belt system on. Or just keep cleaning the dust and buying new belts.

He's talking about Gates Fleetrunner belts. That's all I run.

Gates green stripe, no dust, still looks good after cant remember how many years. Took this pic last week thinking i should replace it.